"This was a room within a room, a way to make the space more comfortable," Lundberg said to Business Insider.

The idea of making something old new again makes sense for a company like Twitter, who chose to move their headquarters to a building that had stood empty for more than a decade. Their relocation there has already led to positive change in the neighborhood.

Twitter moved into its space at 1355 Market Street in June of 2012. Located in the notoriously seedy Mid-Market area of San Francisco, the large warehouse building they chose was previously home to SF Mart, a run-down furniture warehouse. It had sat vacant for nearly 15 years, and violent crime, drugs, and prostitution had became more prevalent in the area.

Matt Rosoff

Finding a tenant for the SF Mart building had proven to be a daunting task for the city. "It's kind of this dead zone that invites the worst of urban life," Lundberg said. "We knew we had the opportunity to do something good for San Francisco by being there."

Plus, moving into a mostly empty building would give the company plenty of space to grow. Twitter currently occupies a whopping 750,000 square feet of space on the fifth through eleventh floors of the SF Mart building. A bright green roof deck has brought a decidedly different feel to the blighted area.

And the neighborhood is changing quickly — lots of people are out and about, and a number of high-rise luxury apartment buildings are under construction. "Market Street is undergoing a renaissance," Lundberg said. "We gave it a big push that we’re now seeing the benefits of."

Matt Rosoff

Here's another look at that awesome roof deck.

Jasper Sanidad

Big things are happening inside Twitter as well. Lundberg Design and Interior Architects recently completed the second phase of their design for the company's headquarters. Dining spaces on the fifth and ninth floors were drastically increased.

But perhaps the project's most talked about features were the two log cabins architects installed on either side of a staircase near the fifth floor dining area.

Jasper Sanidad

The log cabins function as a sort of room within a room, making the space more comfortable. The idea of using reclaimed materials fit in nicely with the designers' theme of revitalization. "The cabins tied in with the aesthetic," Lundberg said. "Sustainable, natural materials — that kind of warm, coffeehouse aesthetic."

Jasper Sanidad

Lundberg had spotted several vintage cabins while prowling Craigslist early on in his work for Twitter. He settled on a pair of 100-year-old cabins from Montana after being referred by an engineering firm.

Jasper Sanidad

But actually installing the structures ended up being a pretty complicated process. The cabins first had to be dismantled and shipped to a shop in Vallejo, about 30 miles outside of San Francisco. There, workers from Beckmann Engineering and Lundberg's shop rebuilt the cabins to the dimensions appropriate for Twitter's office.

Jasper Sanidad

Workers carefully numbered each log so they would know where it was meant to be placed. They then dismantled the cabins from the workshop and brought them over to Twitter headquarters, where they would build them all over again.

Jasper Sanidad

It took about two weeks to finish installing the cabins at Twitter. Just like any other building in California, the structures had to be braced so they would be sturdy during an earthquake.

Jasper Sanidad

Each of the cabins was built around a large existing column. Once construction was complete, they would mount TVs on the column. By the time work was done, it had been nearly five months since Lundberg first chose the cabins they would use for the project.

Jasper Sanidad

Today, the cabins are a place where Twitter employees can go to hang out. A couch and coffee table in each corner make for an interesting meeting spot.

Jasper Sanidad

Twitter's newly expanded office has lots of quirky spaces, like this semi-private library.

Jasper Sanidad

An office gym gives employees an opportunity to unwind.

Jasper Sanidad

There's also these chalkboards that work well both for brainstorming and leaving messages.